cfg80211/mac80211: avoid bss color setting in non-HE modes

Adding bss-color configuration is only valid in HE mode.
Earlier we have enabled it by default, irrespective of
capabilities/mode. Fix that.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: P Praneesh <ppranees@codeaurora.org>
Link: https://lore.kernel.org/r/1594262781-21444-1-git-send-email-ppranees@codeaurora.org


[fix up commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>